Many automobiles today are hybrid vehicles that utilize two or more propulsion systems. For example, certain hybrid vehicles (often referred to as mild hybrid vehicles) utilize an electric motor and battery to assist an internal combustion engine for operation of the vehicle. Other hybrid vehicles (often referred to as full hybrid vehicles) have separate propulsion systems (namely, an electric motor and battery propulsion system and an internal combustion engine propulsion system) that can assist one another or operate independently from one another depending on the circumstances for operation of the vehicle. Yet other hybrid vehicles (often referred to as plug-in hybrid vehicles) predominantly utilize an electric motor and battery propulsion system for operation of the vehicle, but also have a back-up internal combustion engine propulsion system for use when necessary.
Motor torque for hybrid vehicles is typically controlled based on electric feedback current provided by an electric current sensor of the vehicle. Typically, the hybrid system is turned off if the electric current sensor is unhealthy or if there is uncertainty as to whether the electric current sensor is healthy. However, such action may not always be optimal, for example, if the feedback current is typically provided along a communications bus and the bus is unhealthy.